Jinja (template engine)

<h2 id="features">Features</h2>
Some of the features of Jinja are:<a class="footnote-ref" id="fnref:9" href="#fn:9">9</a>

<ul><li>sandboxed execution</li>
<li>automatic <a href="/facts/HTML_escaping/Q8LSfvma">HTML escaping</a> to prevent <a href="/facts/Cross-site_scripting/dhtusKKm">cross-site scripting</a> (XSS) attacks</li>
<li>template inheritance</li>
<li>compiles down to the optimal Python code just-in-time</li>
<li>optional ahead-of-time template compilation</li>
<li>easy to debug (for example, line numbers of exceptions directly point to the correct line in the template)</li>
<li>configurable syntax</li></ul>
Jinja, like <a href="/facts/Smarty_(template_engine)/ayxNIBqT">Smarty</a>, also ships with an easy-to-use filter system similar to the <a href="/facts/Unix/0pNL2seI">Unix</a> <a href="/facts/Pipeline_(Unix)/EIhovuT2">pipeline</a>.

<h2 id="syntax">Syntax</h2>
The syntax for printing output in Jinja is using the double curly braces, for example {{ Hello, World! }}.
Statements which set variables in jinja or those which do not have an output can be wrapped within {% and %}, using the set keyword. For example {% set foo = 42 %} sets a variable called foo with a value of 42.
Similar to above, comments in jinja can be written using a number sign (#) instead of a percentage (%), for example, {# helpful comment #}.
The syntax for creating a filter in Jinja is a <a href="/facts/Vertical_bar/Yq77nJ6f">vertical bar</a> (|), for example {{ variable|filter }}. A variable can have multiple filters, for example {{ variable|filter|filter }}).<a class="footnote-ref" id="fnref:10" href="#fn:10">10</a>
The syntax for creating a test in Jinja is the keyword is as well as the conditions for evaluating the validity of a test, such as for example {% if variable is divisibleby 10 %}do something{% endif %}).<a class="footnote-ref" id="fnref:11" href="#fn:11">11</a>
<a href="/facts/For_loop/cwV2nRzp">For loops</a> can be used to iterate over sequences, while retaining their object properties. The following example demonstrates iterating over a list of users with username and password fields.

{% for user in users %}
 {{ user.username }}
 {{ user.password }}
{% endfor %}

Although break and continue are not allowed inside loops, sequences can be filtered.

<h2 id="example">Example</h2>
Here is a small example of a template file example.html.jinja:<a class="footnote-ref" id="fnref:12" href="#fn:12">12</a>

<!DOCTYPE html>
<html>
 <head>
 <title>{{ variable|escape }}</title>
 </head>
 <body>
 {%- for item in item_list %}
 {{ item }}{% if not loop.last %},{% endif %}
 {%- endfor %}
 </body>
</html>

and templating code:from jinja2 import Template
with open("example.html.jinja") as f:
 tmpl = Template(f.read())
print(tmpl.render(
 variable = "Value with <unsafe> data",
 item_list = [1, 2, 3, 4, 5, 6]
))

This produces the HTML string:

<!DOCTYPE html>
<html>
 <head>
 <title>Value with &lt;unsafe&gt; data</title>
 </head>
 <body>
 1,
 2,
 3,
 4,
 5,
 6
 </body>
</html>
Note the <a href="/facts/Hyphen-minus/TnWuz7hd">minus sign</a> (-) after the tag {%: If you add a minus sign (-) to the start or end of a block (e.g. a For tag), a comment, or a variable expression, the whitespaces before or after that block will be removed.<a class="footnote-ref" id="fnref:13" href="#fn:13">13</a>

<h2 id="external-links">External links</h2>
<ul><li><a href="https://palletsprojects.com/p/jinja/">Official website</a></li></ul>

<h2 id="references">References</h2>

<ol>
<li id="fn:1">"Extensions". Jinja2 Documentation (2.8-dev). Retrieved 2015-05-26. <a href="https://jinja.palletsprojects.com/en/2.11.x/extensions/#module-jinja2.ext" target="_blank">https://jinja.palletsprojects.com/en/2.11.x/extensions/#module-jinja2.ext</a> <a href="#fnref:1" class="footnote-back-ref">↩</a></li>
<li id="fn:2">"Jinja built-in filters and tests (like Django filters)". www.webforefront.com. Retrieved 2023-08-14. <a href="https://www.webforefront.com/django/usebuiltinjinjafilters.html" target="_blank">https://www.webforefront.com/django/usebuiltinjinjafilters.html</a> <a href="#fnref:2" class="footnote-back-ref">↩</a></li>
<li id="fn:3">"Jinja built-in filters and tests (like Django filters)". www.webforefront.com. Retrieved 2023-08-14. <a href="https://www.webforefront.com/django/usebuiltinjinjafilters.html" target="_blank">https://www.webforefront.com/django/usebuiltinjinjafilters.html</a> <a href="#fnref:3" class="footnote-back-ref">↩</a></li>
<li id="fn:4">"Extensions". Jinja2 Documentation (2.8-dev). Retrieved 2015-05-26. <a href="https://jinja.palletsprojects.com/en/2.11.x/extensions/#expression-statement" target="_blank">https://jinja.palletsprojects.com/en/2.11.x/extensions/#expression-statement</a> <a href="#fnref:4" class="footnote-back-ref">↩</a></li>
<li id="fn:5">DuPlain, R. (2013). Instant Flask Web Development. Packt Publishing. p. 30. ISBN 978-1-78216-963-5. Retrieved 2015-05-26. <a href="978-1-78216-963-5" target="_blank">978-1-78216-963-5</a> <a href="#fnref:5" class="footnote-back-ref">↩</a></li>
<li id="fn:6">"Templating (Jinja2) — Ansible Documentation". <a href="https://docs.ansible.com/ansible/latest/user_guide/playbooks_templating.html" target="_blank">https://docs.ansible.com/ansible/latest/user_guide/playbooks_templating.html</a> <a href="#fnref:6" class="footnote-back-ref">↩</a></li>
<li id="fn:7">"Understanding Jinja". docs.saltproject.io. <a href="https://docs.saltproject.io/en/latest/topics/jinja/index.html" target="_blank">https://docs.saltproject.io/en/latest/topics/jinja/index.html</a> <a href="#fnref:7" class="footnote-back-ref">↩</a></li>
<li id="fn:8">Jinja and macros | dbt Developer Hub <a href="https://docs.getdbt.com/docs/build/jinja-macros" target="_blank">https://docs.getdbt.com/docs/build/jinja-macros</a> <a href="#fnref:8" class="footnote-back-ref">↩</a></li>
<li id="fn:9">"Welcome | Jinja2 (The Python Template Engine)". palletsprojects.com/p/jinja. <a href="https://palletsprojects.com/p/jinja/" target="_blank">https://palletsprojects.com/p/jinja/</a> <a href="#fnref:9" class="footnote-back-ref">↩</a></li>
<li id="fn:10">"Jinja built-in filters and tests (like Django filters)". www.webforefront.com. Retrieved 2023-08-14. <a href="https://www.webforefront.com/django/usebuiltinjinjafilters.html" target="_blank">https://www.webforefront.com/django/usebuiltinjinjafilters.html</a> <a href="#fnref:10" class="footnote-back-ref">↩</a></li>
<li id="fn:11">"Jinja built-in filters and tests (like Django filters)". www.webforefront.com. Retrieved 2023-08-14. <a href="https://www.webforefront.com/django/usebuiltinjinjafilters.html" target="_blank">https://www.webforefront.com/django/usebuiltinjinjafilters.html</a> <a href="#fnref:11" class="footnote-back-ref">↩</a></li>
<li id="fn:12">Ronacher, Armin. "Template Designer Documentation". Jinja Documentation (3.0.x). Retrieved 9 January 2024. A Jinja template doesn't need to have a specific extension: .html, .xml, or any other extension is just fine. <a href="https://jinja.palletsprojects.com/en/3.0.x/templates/" target="_blank">https://jinja.palletsprojects.com/en/3.0.x/templates/</a> <a href="#fnref:12" class="footnote-back-ref">↩</a></li>
<li id="fn:13">"Template Designer Documentation — Jinja Documentation (3.0.x)". jinja.palletsprojects.com. Retrieved 2024-01-09. <a href="https://jinja.palletsprojects.com/en/3.0.x/templates/#whitespace-control" target="_blank">https://jinja.palletsprojects.com/en/3.0.x/templates/#whitespace-control</a> <a href="#fnref:13" class="footnote-back-ref">↩</a></li>
</ol>

Jinja (template engine) open-in-new

Jinja (template engine)